EU regulators are pushing for Google to make significant changes to its mobile service as part of efforts to settle an antitrust investigation, a London newspaper reports.

The Financial Times said the outcome of the case could rest on Google's "willingness" to extend the scope of the settlement to mobile services, which would include mobile search and advertising as part of the agreement should Google wish to settle.

EU Competition Commissioner Joaquin Almunia is pushing for a swift outcome to the case, but only should certain conditions be met. Swift outcome or not, Almunia said that "formal proceedings will continue" if the EU doesn't get its way.

Talks between the search giant and European officials are said to be on a "knife-edge," reports Reuters, with an expectation that Almunia could decide as early as next week on a decision whether to charge the company or not.

The case stems back to the EU's concerns that Google is pushing out competitors by "copying" content from other sites, and makes it more difficult for advertisers to move away to rival search engines, among others.

The initial letter sent by Schmidt to Almunia addressed the "four areas the European Commission described" in June -- which can be found here. The details of the letter were not disclosed, however.

Should Google fail to settle the case, the search giant will be served an official antitrust complaint in form of a statement of objections, which opens the door to a fine of up to 10 percent of its global annual revenue -- close to $4 billion.

A Google spokesperson said, "We continue to work cooperatively with the European Commission," according to sister site CNET.